scholarly journals Computational and experimental investigations of one-step conversion of poly(carbonate)s into value-added poly(aryl ether sulfone)s

2016 ◽  
Vol 113 (28) ◽  
pp. 7722-7726 ◽  
Author(s):  
Gavin O. Jones ◽  
Alexander Yuen ◽  
Rudy J. Wojtecki ◽  
James L. Hedrick ◽  
Jeannette M. García
Keyword(s):  
High Performance ◽  
Density Functional ◽  
Value Added ◽  
Single Step ◽  
Nucleophilic Attack ◽  
Experimental Investigations ◽  
Aryl Ether ◽  
One Step ◽  
Poly Carbonate

It is estimated that ∼2.7 million tons poly(carbonate)s (PCs) are produced annually worldwide. In 2008, retailers pulled products from store shelves after reports of bisphenol A (BPA) leaching from baby bottles, reusable drink bottles, and other retail products. Since PCs are not typically recycled, a need for the repurposing of the PC waste has arisen. We report the one-step synthesis of poly(aryl ether sulfone)s (PSUs) from the depolymerization of PCs and in situ polycondensation with bis(aryl fluorides) in the presence of carbonate salts. PSUs are high-performance engineering thermoplastics that are commonly used for reverse osmosis and water purification membranes, medical equipment, as well as high temperature applications. PSUs generated through this cascade approach were isolated in high purity and yield with the expected thermal properties and represent a procedure for direct conversion of one class of polymer to another in a single step. Computational investigations performed with density functional theory predict that the carbonate salt plays two important catalytic roles in this reaction: it decomposes the PCs by nucleophilic attack, and in the subsequent polyether formation process, it promotes the reaction of phenolate dimers formed in situ with the aryl fluorides present. We envision repurposing poly(BPA carbonate) for the production of value-added polymers.

scholarly journals Gallium nitride catalyzed the direct hydrogenation of carbon dioxide to dimethyl ether as primary product

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Chang Liu ◽  
Jincan Kang ◽  
Zheng-Qing Huang ◽  
Yong-Hong Song ◽  
Yong-Shan Xiao ◽  
...  
Keyword(s):  
Gallium Nitride ◽  
Dimethyl Ether ◽  
High Performance ◽  
Density Functional ◽  
Value Added ◽  
Density Functional Theory Calculations ◽  
Product Distribution ◽  
Spectroscopic Studies ◽  
Direct Hydrogenation ◽  
Hydrogenation Of Co

AbstractThe selective hydrogenation of CO2 to value-added chemicals is attractive but still challenged by the high-performance catalyst. In this work, we report that gallium nitride (GaN) catalyzes the direct hydrogenation of CO2 to dimethyl ether (DME) with a CO-free selectivity of about 80%. The activity of GaN for the hydrogenation of CO2 is much higher than that for the hydrogenation of CO although the product distribution is very similar. The steady-state and transient experimental results, spectroscopic studies, and density functional theory calculations rigorously reveal that DME is produced as the primary product via the methyl and formate intermediates, which are formed over different planes of GaN with similar activation energies. This essentially differs from the traditional DME synthesis via the methanol intermediate over a hybrid catalyst. The present work offers a different catalyst capable of the direct hydrogenation of CO2 to DME and thus enriches the chemistry for CO2 transformations.

In Situ One-Step Synthesis of Hierarchical Nitrogen-Doped Porous Carbon for High-Performance Supercapacitors

2014 ◽  
Vol 6 (10) ◽  
pp. 7214-7222 ◽  
Author(s):  
Ju-Won Jeon ◽  
Ronish Sharma ◽  
Praveen Meduri ◽  
Bruce W. Arey ◽  
Herbert T. Schaef ◽  
...  
Keyword(s):  
Porous Carbon ◽  
High Performance ◽  
Nitrogen Doped ◽  
One Step

A one-step strategy for aliphatic poly(carbonate-ester)s with high performance derived from CO2 , propylene oxide and l -lactide

2016 ◽  
Vol 28 (6) ◽  
pp. 736-741 ◽  
Author(s):  
Pengfei Song ◽  
Haidong Xu ◽  
Xudong Mao ◽  
Xiaojun Liu ◽  
Lei Wang
Keyword(s):  
Propylene Oxide ◽  
High Performance ◽  
One Step ◽  
Poly Carbonate

One-Step In Situ Growth of Iron-Nickel Sulfide Nanosheets on FeNi Alloy Foils: High-Performance and Self-Supported Electrodes for Water Oxidation

Small ◽  
2017 ◽  
Vol 13 (18) ◽  
pp. 1604161 ◽  
Author(s):  
Cheng-Zong Yuan ◽  
Zhong-Ti Sun ◽  
Yi-Fan Jiang ◽  
Zheng-Kun Yang ◽  
Nan Jiang ◽  
...  
Keyword(s):  
Water Oxidation ◽  
High Performance ◽  
Nickel Sulfide ◽  
In Situ Growth ◽  
Iron Nickel ◽  
One Step ◽  
Feni Alloy

scholarly journals A Novel One-step Synthesis of Quinoline-2(1H)-thiones and Selones by Treating 3-Aryl-3-(2-aminophenyl)-1-propyn-3-ols with a Base and Elemental Sulfur or Selenium

2015 ◽  
Vol 10 (6) ◽  
pp. 1934578X1501000 ◽  
Author(s):  
Kazuaki Shimada ◽  
Hironori Izumi ◽  
Koki Otashiro ◽  
Kensuke Noro ◽  
Shigenobu Aoyagi ◽  
...  
Keyword(s):  
Elemental Sulfur ◽  
Reactive Species ◽  
Nucleophilic Attack ◽  
Amino Group ◽  
One Step ◽  
High Yields

A one-step conversion of 3-aryl-3-(2-aminophenyl)-1-propyn-3-ols into quinoline-2(1 H)-thiones and quinoline-2(1 H)-selones was achieved only by treating the substrates with n-butyllithium and either elemental sulfur or selenium, respectively. The reactions were assumed to proceed through an intramolecular nucleophilic attack of the neighboring amino group to the plausible in situ generated reactive species related to chalcogenoketenes. The subsequent mCPBA oxidation of quinoline-2(1 H)-selones afforded quinolin-2(1 H)-ones in high yields.

scholarly journals Highly efficient single-step pretreatment to remove lignin and hemicellulose from softwood

BioResources ◽  
2019 ◽  
Vol 14 (2) ◽  
pp. 3567-3577
Author(s):  
Irma Bernal-Lugo ◽  
Carmen Jacinto-Hernandez ◽  
Miquel Gimeno ◽  
C. Carmina Montiel ◽  
Fausto Rivero-Cruz ◽  
...  
Keyword(s):  
Value Added ◽  
Enzymatic Digestion ◽  
Single Step ◽  
Glucose Yield ◽  
Highly Efficient ◽  
First Case ◽  
Hemicellulose Removal ◽  
One Step ◽  
Low Glucose ◽  
Hydrolysis Of

The use of lignocellulosic softwood residues as feedstock for the production of bioethanol and other value-added chemical products has been limited by its high recalcitrance. Alkaline or organosolvent pretreatments have been used to remove recalcitrance in softwoods. Although these methods partially remove lignin and hemicellulose, they also result in low glucose recovery. In the first case, there is low cellulose hydrolizability, and in the second, there is a loss of cellulose. This study evaluated both methods combined into one step: alkaline hydrolysis of the biomass in the presence of an organosolvent. Different conditions of temperature and residence times were assayed. The efficiency of these conditions was quantified as the percentage of lignin and hemicellulose removed from the biomass without loss of cellulose. The substrate produced with the most efficient conditions removed 91% of the lignin and 89.1% of the hemicellulose with no loss of cellulose. Enzymatic hydrolysis of this biomass was 90% to 95%, with a substrate concentration of 3% and with five filter paper units per gram of cellulose (FPU/g cellulose). These results indicated that this one-step alkaline-organsolvent process, applied as a pretreatment to softwood, allows highly efficient lignin and hemicellulose removal. 100% of cellulose was recovered, and there was between 90 and 95% glucose yield after enzymatic digestion.

scholarly journals Chemistry and Mechanism of One-Step Formation of Graphene from Agrowaste

2020 ◽  
Vol 9 (3) ◽  
pp. 1389-1394
Keyword(s):  
Sugarcane Bagasse ◽  
High Performance ◽  
Graphene Nanosheets ◽  
Atmospheric Condition ◽  
Single Step ◽  
Xrd Pattern ◽  
Graphene Derivatives ◽  
One Step ◽  
The One ◽  
First Time

The one-step synthesis of high-quality graphene derivatives via CVD process has gained considerable importance nowadays for high-performance electronics and sensors. However, the use of harsh chemicals, high temperature, sensitivity, and the problem of separation of graphene from the substrate, motivated the one-step synthesis of graphene from a non-graphitic precursor, bypassing the use of graphite. In this paper, we have reported for the first time, the synthesis of graphene nanosheets from sugarcane bagasse at the normal atmospheric condition in a single step, avoiding the formation of GO. Here, the pyrolysis of sugarcane bagasse was carried out in the temperature range of 250-450o C in the presence of sodium hydroxide. The results suggested that even the low temperature (250–450o C) facilitated the development of graphitic planes via condensation and aromatization of the glucose monomers present in the precursor. The XRD pattern showed 2θ at around 25o in each case, which confirmed the formation of graphene instead of GO. The FESEM, TEM, and EDX analysis proved the formation of few-layer nanosheets of graphene from carbon-rich waste precursors in a single step.

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